The search for extraterrestrial life is by no means new, dating as far back as 5 BCE to philosophers Aristotle, Plato, Epicurus, and Democritus. And while their hypotheses didn’t rest on fact or scientific method, but instead on philosophy, it’s incredibly clear that we have always been intrigued by the possibility of life beyond our own.
Over 2,000 years later and we’re not much closer to an answer, but it hasn’t been without trying.
Some early attempts communicating with extraterrestrial life have been through the Pioneer Plaque in 1972, and the Voyager Golden Record in 1977. The Pioneer Plaque, actually being two separate plaques on two separate crafts (Pioneers 10 and 11), are plaques with engravings of a nude man waving hello and a woman beside him, while giving Earth’s coordinates within the galaxy. The Voyager Golden Record, also being two records on Voyagers 1 and 2, contain music, nature sounds, and images, in the hopes of depicting life on Earth. According to NASA, Voyager 1 is currently “the farthest man-made object from Earth and the first spacecraft to reach interstellar space.”
While both experiments were led by Carl Sagan and were well meaning, it has been agreed by most within the academic community that the attempts were more for the sake of humanity than as an attempt to communicate with extraterrestrial life.
“I think that there is a sense of aspirational unity and hopefulness in the desire to communicate in this way, and while I don’t expect that they will ever be picked up or prompt a response, there is something pleasing to me about imagining these satellites carrying these messages, music, and sounds of Earth to the edge of our solar system and beyond,” adds Dr. Rachel Ward-Maxwell, researcher-programmer of Astronomy & Space Sciences at the Ontario Science Centre.
“The value of the efforts such as the design and launching of the Pioneer Plaque and Voyager Golden Records lie in that it tells us more about ourselves and our understanding of humankind as a civilization,” explains Dr. Parandis Tajbakhsh, who teaches Extraterrestrial Life: A Modern Discussion to include Historical, Religious and Cultural Aspects at York, and has a PhD in astronomy and astrophysics. “Even if ever found by another intelligent civilization, it is quite unlikely that the message encoded in these artifacts could ever be understood.”
In recent years, the goal has shifted from trying to communicate with possible extraterrestrial life to understanding how life could survive in space at all. While we are in the infancy stages of discovering this, recent focuses have been on extremophiles like tardigrades.
“Extremophiles are bacteria that can live in really extreme environments, and that makes sense if you’re thinking about it from ‘how does life get moving?’ Life grabs on where it can and so it would make sense that life would begin as an extremophile because all environments are extreme,” says Dr. Jesse Rogerson, assistant professor with a background in astronomy studying supermassive black holes.
Chris Rutkowski, considered to be Canada’s top Ufology expert who has a background in astronomy, agrees that extremophiles may hold the answer to the possibility of extraterrestrial life.
“I’d point to tardigrades, an extremophile also known as ‘water bears,’ which seem to be able to survive in space and in hostile environments. This could mean that if life is possible, it is probable. So, if there is an environment where we think life could exist (like the ocean of Enceladus), then there is a pretty good chance it’s there. It might be that life of some kind is abundant in the universe,” says Rutkowski.
Dr. Ward-Maxwell also adds that gaining a better understanding of extremophiles will “definitely inform our hunt for potential life in the universe.”
“Bacteria have been found surviving in permafrost, thriving near the intense heat of hydrothermal vents, and resisting the damaging radiation on the exterior of the International
Space Station (ISS), demonstrating the range of conditions where life can exist. This can be extended to our search for microbial life in extreme environments on other worlds, such as the subsurface liquid water on the icy moons of the outer solar system like Europa and Enceladus and the liquid methane and ethane lakes on Titan.”
“The ability for bacteria to survive in space also suggests that life could possibly move between bodies in our solar system,” Dr. Ward-Maxwell adds.
Because the search for the possibility for life has become so intricate, NASA has recently introduced a seven-step framework by Jim Green, for evaluating the data we find on other planets that’s “reflective of the winding, complicated staircase of steps that would lead to scientists declaring they’ve found life beyond Earth,” they report.
However, Dr. Seth Shostak, senior astronomer at the Search for Extraterrestrial Intelligence (SETI) Institute, has his doubts as to the effectiveness of the framework, comparing it to a similar one used in the past, called the Rio Scale.
“It hasn’t turned out to be very useful. And the reason is, somebody says, ‘I think I’ve found evidence for life on Mars’ but the problems with it are who’s making the decision about how it ranks and if they’re competent enough to make that decision. You don’t need a scale because nobody can fill in the scale unless they’re sort of an expert on that subject. The second reason it’s not terribly useful, in my opinion, is that the public doesn’t know how to interpret that.
If they said, ‘this indication of life on Mars is a five,’ the question remains ‘is there life on Mars or not?’”
Dr. Rogerson notes that in the search for extraterrestrial life, “Where an astronomer fits in would be in observing radio light, listening for communication, or looking at exoplanets and their atmospheres, which is very new.”
SETI Institute currently does look for possible signals from intelligent life forms though, with Dr. Shostak stating, “SETI has been working since 1960, so that’s 60 to 70 years to try and eavesdrop on these signals — whether they’re radio signals or they’re flashing lasers, or what else.”
Dr. Shostak continues: “But I think that you also could say it’s something we don’t do very systematically, because it’s unclear how to do it systematically. What might be better than listening for signals, is to look for artifacts.”
“At the conservatory there’s 42 antennas spread across the northern California landscape, and they’re trying to pick up a signal. But the assumption is that a signal will arrive at the telescopes, just at the time that we’re looking. If they beam something at Earth, for example, and they beamed it to arrive at Earth 100 years ago, we wouldn’t see them. And if they beam it so it arrives 100 years from now, we probably won’t see it with any of the existing telescopes. So it requires this synchronicity. And that may be the difficulty.”
While the answers are only somewhat clearer than they were in 5 BCE, experts are unanimous that the current ‘Billionaire Space Race’ isn’t the answer to finding extraterrestrial life or for saving humanity.
“If you could terraform Mars, you can certainly fix Earth,” says Rogerson. “If you can change the atmosphere there, then change the atmosphere here, but it has value in that you learn about the place.”
Dr. Ward-Maxwell does point out, however, that our presence from these missions may be more harmful to extraterrestrial life, as opposed to focusing on how its presence would affect us.
“There are certain planetary protections currently in place, like those outlined in the Outer
Space Treaty, which state that exploration of celestial bodies must be done in such a way as
to prevent biological contamination and changes to the environment.
“The planned Artemis missions to the Moon and Mars are causing these policies to be reviewed and, in some cases, changed to allow for the advancement of human exploration,” Dr. Ward-Maxwell continues. “It is important to prioritize the potential for microbial life and habitable regions, and that any approach must be carefully considered and informed by research, not profit, to ensure the necessary protections.”
Rutkowski also points out that a possible — and maybe only — benefit the Artemis mission will have on the search for extraterrestrial life is “that being away from Earth’s electromagnetic pollution will allow us to examine the universe at wavelengths that might yield interesting discoveries.”
While the search for extraterrestrial life is still largely a philosophical question, crucial first steps are being taken to locate and understand all types of life and the universe- and our place within it.